As I mentioned, I’m currently upstate with my parents. The old house they live in is on a “farm-ette,” as it’s apparently called. It’s something like 5 acres and it was used as a horse farm before they got it. My mom’s been trying her hand at gardening–she’s got those raised table beds so it’s really easy to “farm.”
Delta is the symbol used to denote change in mathematic and scientific equations. For example, students are taught that velocity = change in position / change in time. That equation is often given as v=(x-x)/(t-t) [with the first x and t having subscript 2 and the second x and t having subscript 1 to denote that they are two discrete location and time coordinates, but I can’t figure out how to get subscript characters in WordPress!] This, of course, is more simply written as v=∆x/∆t. In other words, a delta represents not some nebulous concept of change but a specific, measurable change between two distinct points in time (or space).